Process for preparing a product from a pulse crop as a starting material and a food containing the product prepared from a pulse crop as a starting material

ABSTRACT

A process for preparing a product from a pulse crop as a starting material and a food containing the product prepared from a pulse crop as a starting material are disclosed according to the present invention, thereby enabling a food, a livestock feed, an aquacultural feed or the like to be efficiently prepared, which is made from a leguminous crop or a defatted product thereof or the like, which has excellent carcinopreventive and carcinostatic activities, osteoprosis therapeutic effect and immunosuppressive effect, and which can be ingested in a sufficient amount, and thereby enabling a wholesome food such as a biscuit having the above-mentioned excellent pharmacological activities. Any conventional product made from a pulse crop does not have such excellent pharmacological activities and a process for preparing the same is poor in efficiency. Significant characteristic feature of the present invention resides in that glycosidic saccharides are hydrolytically separated from isoflavone compounds contained in a pulse crop to form isoflavone compounds containing aglycones in a large amount and that phytic acid contained in a pulse crop is removed to obtain a product having excellent pharmacological activities.

This application is based upon the International ApplicationPCT/JP94/02103, the International Publication Number WO95/16362published on Jun. 22, 1995.

TECHNICAL FIELD

The present invention relates to a process for preparing a product froma pulse crop as a starting material and a food containing the productprepared from a pulse crop as a starting material.

In the present invention, the term "pulse crop" means leguminous cropssuch as soybean, defatted products thereof and the like, and the term"product made from a pulse crop as a starting material" means foods,livestock feeds, aquacultural feeds and the like which are made from theabove-mentioned pulse crop.

BACKGROUND ART

In general, soybean which is one of the pulse crops contains isoflavonecompounds including daidzin, daidzein, genistin and genistein.

The isoflavone compounds are represented by the following formula andDenotative Table.

    ______________________________________     ##STR1##    Denotative Table                  R1        R2    ______________________________________    daidzin         H           glucose    daidzein        H           H    genistin        OH          glucose    genistein       OH          H    ______________________________________

Of these isoflavone compounds, daidzein is an aglycone of daidzin havingits glucose as a glycosidic saccharide hydrolytically separatedtherefrom, and genistein is an aglycone of genistin having its glucoseas a glycosidic saccharide hydrolytically separated therefrom. Withrespect to the isoflavone compounds, contents thereof and percentagesbetween daidzin and daidzein and between genistin and genistein in adefatted soybean are as shown in the following Table 1.

                  TABLE 1    ______________________________________               daidzin                     daidzein  genistin                                       genistein    ______________________________________    defatted soybean                 100     3.2       180   4.2                 (96.9%) (3.1%)    (97.7%)                                         (2.3%)    ______________________________________     (unit: mg/100g)

It is understood from Table 1 that, in soybean, daidzin and genistin arecontained in larger amounts while daidzein and genistein which areaglycones thereof are contained in smaller amounts.

On the other hand, it has been reported that a glycosidic saccharide ishydrolyzed from an isoflavone compound contained in soybean to form anaglycone in the course of soy sauce or miso (fermented soybean paste)preparation see Sho-Ken (Soy-research) by Kiyoshi Kihara, vol.16, No.5,page 190 (1990)!.

According to this report, however, although hydrolysis of a glycosidicsaccharide proceeds to some extent by cooking of a defatted soybean orin a koji preparation step, most of the saccharide has alreadyhydrolytically been separated in soy sauce sediment or soybean miso.Accordingly, it is difficult to employ these for a process for preparinga product from a pulse crop as a starting material.

Further, many reports have been made on pharmacological activities ofaglycones derived from hydrolysis of glycosidic saccharides fromisoflavone compounds.

For example, genistein has been ascertained to be a tyrosine kinaseinhibitor (TK inhibitor). Since tyrosine kinase is essentiallyresponsible for cancer-induction by an onocogene, carcinostaticactivities of genistein as a TK inhibitor are confirmed and the effectthereof has drawn attention Akiyama et al.: Biochemistry, vol.59, No.9,page 1016 (1987)!.

Further, estrogenic activities of an isoflavone compound have alsoattracted attention and have been confirmed to have osteoprosistherapeutic effect and immunosuppressive effect. In particular,genistein which is an aglycone of an isoflavone compound has notableestrogenic activities, and this activities enable osteopenia (boneresorption) to be suppressed.

Accordingly, many proposals concerning isoflavone compounds contained insoybean have been made in Japanese Unexamined Patent PublicationNo.126,186/1987, Japanese Unexamined Patent Publication No.258,669/1989,Japanese Unexamined Patent Publication No.170,756/1993, and so on.

DISCLOSURE OF INVENTION

According to the method described in Japanese Unexamined PatentPublication No.126,186/1987, however, most of the resulting isoflavonecompounds are daidzin and genistin which each have a glycosidicsaccharide, and aglycones are contained in the resultant in smallamounts. Thus, it is impossible to obtain foods and the like which haveexcellent pharmacological effect as mentioned above.

The method described in Japanese Unexamined Patent PublicationNo.258,669/1989 is one which comprises hydrolytically separating aglycosidic saccharide from an isoflavone compound by action ofβ-glucosidase which is one of enzymes contained in soybean per se.However, aglycones are formed in a small proportion.

The method described in Japanese Unexamined Patent PublicationNo.170,756/1993 is one which comprises extractively separatingisoflavone compounds from aglycones of isoflavones formed in a soy saucesediment or soy sauce. Although aglycones of isoflavones are formed inthe course of soy sauce preparation and yet formed in a very highproportion as described above, there is the following disadvantage. Thatis, aglycones of isoflavones are present in soy sauce sediment becauseof their insolubility and soy sauce sediment per se does not serve as afood, and hence the method cannot be employed as a method for preparinga food. Further, aglycones of isoflavones are also formed in a soybeanmiso at initial stage of preparation. However, a soybean miso has aproblem that it should be avoided to ingest a soybean miso in a largeamount because it is a highly salinized food.

Although ingestion of foods in a satisfactory amount which contain asufficient amount of such isoflavone aglycones having excellentpharmacological activities as mentioned above enables dietarily desiredlife to be realized which exhibits excellent effect in terms of healthmaintenance of a human being, no food has heretofore satisfied thisexpectation.

Thus, the advent of foods which have excellent carcinopreventive andcarcinostatic activities, osteoprosis therapeutic activities, andimmunosuppressive activities, and which can be ingested in asatisfactory amount.

With respect to osteoprosis, it is desired to remove phytic acid, whichinhibits calcium from being absorbed in a body, from a pulse crop.

In soybean which is one of beans, phytic acid is contained in an amountof about 1 to 2% by weight. Phytic acid is residually present also in aproduct made from soybean and inhibits activities of a vitamin B complexcontained in the product to prevent absorption of minerals and the likecontained in the product. Further explanatively, phytic acid is acompound having such a structure that myo-inositol has its all hydroxylgroups each bonded with a phosphoric acid group, and chelates with anutritionally important trace metal element to form hardly solublecompound. Accordingly, when a food with high phytic acid content isingested by a human being or animal, normal intestinal absorption ofsuch metals, for example, calcium, magnesium, iron, zinc and the like isprevented to cause various deficiencies. It has further been found thatphytic acid present in a product including a soy protein isolateprevents a monogasteric animal from utilizing zinc in a food. Further,phytic acid is known to have inhibitory activities on various digestiveenzymes in a gastrointestinal digestive tract on which ions of mineralssuch as calcium act as activators and which include α-amylase, pepsinand trypsin. It is, therefore, desired to remove phytic acid from theproduct.

Heretofore, however, it has been impossible to remove phytic acidsuccessfully.

The present invention has been made in view of these points. It is,therefore, an object of the present invention to provide a process forpreparing a product from a pulse crop such as a food, a livestock feed,an aquacultural feed or the like, which is made from a pulse crop, whichhas excellent carcinopreventive and carcinostatic activities,osteoprosis therapeutic effect and immunosuppressive effect, and whichcan be ingested in a sufficient amount.

It is another object of the present invention to provide a healthfulfood, such as a biscuit or the like which contains a product that ismade from a pulse crop and that has properties excellent incarcinopreventive and carcinostatic activities, osteoprosis therapeuticeffect and immunosuppressive effect.

To attain the above object, the process of the present invention forpreparing a product from a pulse crop as a starting material comprises:

inoculating a koji starter on a pulse crop to prepare koji; and

adding water to the resultant from the koji preparation treatment toadvance hydrolysis of a protein contained in the resultant;

wherein in the course of the koji preparation and the proteolysis,separation of glycosidic saccharides from isoflavone compounds containedin the pulse crop is advanced to form isoflavone compounds containingaglycones in a large amount, thereby obtaining a product from the pulsecrop as a starting material.

Further, the process of the present invention for preparing a productfrom a pulse crop as a starting material comprises:

inoculating a koji starter on a pulse crop to prepare koji; and

adding water to the resultant from the koji preparation treatment toadvance hydrolysis of a protein contained in the resultant;

wherein in the course of the koji preparation and the proteolysis,removal of phytic acid is advanced in parallel with the separation ofglycosidic saccharides from isoflavone compounds contained in the pulsecrop to form isoflavone compounds containing aglycones in a largeamount, thereby obtaining a product from the pulse crop as a startingmaterial.

Still further, the food of the present invention containing a productprepared from a pulse crop as a starting material contains a productprepared from a pulse crop as a starting material by steps of:

inoculating a koji starter on a pulse crop to prepare koji; and

adding water to the resultant from the koji preparation treatment toadvance hydrolysis of a protein contained in the resultant;

wherein in the course of the koji preparation and the proteolysis,separation of glycosidic saccharides from isoflavone compounds containedin the pulse crop is advanced to form isoflavone compounds containingaglycones in a large amount, thereby obtaining a product from the pulsecrop as a starting material.

Further, the food of the present invention containing a product preparedfrom a pulse crop as a starting material contains a product preparedfrom a pulse crop as a starting material by steps of:

inoculating a koji starter on a pulse crop to prepare koji; and

adding water to the resultant from the koji preparation treatment toadvance hydrolysis of a protein contained in the resultant;

wherein in the course of the koji preparation and the proteolysis,removal of phytic acid is advanced in parallel with the separation ofglycosidic saccharides from isoflavone compounds contained in the pulsecrop to form isoflavone compounds containing aglycones in a largeamount, thereby obtaining a product from the pulse crop as a startingmaterial.

The present invention is constructed as described above and henceexhibits the following extremely excellent effects.

According to the process of the present invention for preparing aproduct from a pulse crop as a starting material it is realized thatkoji mold is propagated in koji preparation by inoculating koji starteron a pulse crop to hydrolytically separate glycosidic saccharides fromisoflavone compounds contained in the pulse crop, and hydrolysis of aprotein contained in the resultant from the koji preparation treatmentis advanced by adding water thereto in parallel with further hydrolyticseparation of glycosidic saccharides from isoflavone compounds containedin the pulse crop to form isoflavone compounds containing aglycones in alarge amount.

According to the process of the present invention for preparing aproduct from a pulse crop as a starting material it is realized thatkoji mold is propagated in koji preparation by inoculating koji starteron a pulse crop to hydrolytically separate glycosidic saccharides fromisoflavone compounds contained in the pulse crop and concurrentlytherewith to remove phytic acid in the pulse crop, and hydrolysis of aprotein contained in the resultant from the koji preparation treatmentis advanced by adding water thereto in parallel with further hydrolyticseparation of glycosidic saccharides from isoflavone compounds containedin the pulse crop to form isoflavone compounds containing aglycones in alarge amount and in parallel with further removal of phytic acid.

The koji mold as mentioned above produces various enzymes, and of theseenzymes, β-glucosidase, phytase, phosphatase and protease are utilizedto hydrolytically separate glycosidic saccharides from isoflavonecompounds and to remove phytic acid contained in a pulse crop.

The food of the present invention containing a product made from a pulsecrop is a food containing the above-mentioned product made from a pulsecrop. The food contains the product having excellent carcinopreventiveand carcinostatic activities, osteoprosis therapeutic effect,immunosuppressive effect and the like, and accordingly, it is capable ofmaintaining parson's health constantly good when ingested as a healthfood.

The present invention is constructed and functions as described above,and hence the product prepared in accordance therewith is derived from apulse crop and is of excellence in carcinopreventive and carcinostaticactivities, osteoprosis therapeutic effect, immunosuppressive effect andthe like. Further, the product is easy of digestion and yet easy ofabsorption because it is prepared through proteolysis. Accordingly, theproduct is nutritionally excellent in terms of protein utilizationefficiency. In addition, the product can be used for a food, a livestockfeed, an aquacultural feed and the like which may be ingested in asatisfactory amount, because no common salt has been added thereto.

Further, a food such as a biscuit which is so prepared as to contain theabove-mentioned product is one having excellent carcinopreventive andcarcinostatic activities, osteoprosis therapeutic effect,immunosuppressive effect and the like, and accordingly, it is capable ofmaintaining parson's health constantly good when ingested as a healthfood. In particular, genistein in isoflavone compounds containingaglycones in a large amount obtained by hydrolytically separatingglycosidic saccharides from isoflavone compounds is highly effectivebecause of its high carcinopreventive and carcinostatic activities onmastocarcinoma, prostatitic cancer and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart showing one mode of the process for preparing aproduct from a pulse crop according to the present invention, whichcomprises forming aglycones having high pharmacological activities fromisoflavone compounds contained in a defatted soybean, and one mode ofthe process which further comprises concurrently removing phytic acidcontained in the defatted soybean.

FIG. 2 is a diagram showing temperature characteristics of a mixturewith progress of koji preparation time.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, embodiments of the present invention will be described withreference to FIG. 1.

FIG. 1 is a flow chart showing one mode of the process for preparing aproduct from a pulse crop according to the present invention, whichcomprises hydrolytically separating glycosidic saccharides fromisoflavone compounds contained in a defatted product of soybean which isone of pulse crops to form isoflavone compounds containing aglycones ina large amount in the resulting product, and one mode of the processwhich further comprises concurrently removing phytic acid contained inthe defatted soybean.

In the first place, the process for preparing a product will bedescribed, which comprises forming isoflavone compounds containingaglycones in a large amount.

Explanation will be given along the procedure in FIG. 1. First, adefatted soybean is cooked. By effecting the cooking, propagation ofkoji is facilitated. The cooking of the defatted soybean may beconducted batchwise or continuously according to the purpose ofpreparation or the like.

After completion of the cooking, the defatted soybean is once cooled toadjust water content in the defatted soybean to a level allowing koji topropagate (for example, 40% by weight).

Incidentally, when a defatted soybean or the like is used as a startingmaterial, the step of cooking may be omitted.

The defatted soybean thus adjusted in the water content is subjected tothe process of the present invention as follows.

That is, the defatted soybean already cooked is inoculated with a kojistarter of a koji mold at a predetermined weight ratio, and mixing isconducted to uniformness.

Then, the mixture is charged into a device for preparing koji and keptin a heated condition at an initial temperature of about 28° to 30° C.for a predetermined period of time to ferment the defatted soybeanhaving a water content as low as 40% by weight with koji, therebyhydrolytically separating glycosidic saccharides from isoflavonecompounds contained in the defatted soybean to form aglycones. The kojipreparation is continued until an enzyme necessary for hydrolyticallyseparating the glycosidic saccharides from the isoflavone compounds.

In this stage, the koji is propagated on the defatted soybean to produceβ-glucosidase which is an enzyme hydrolytically separating a glycosidicsaccharide from an isoflavone compound, and by this enzyme, glycosidicsaccharides are hydrolytically separated from the isoflavone compoundscontained in the defatted soybean to form aglycones of the isoflavones.

As the koji starter for the koji preparation, there may be used thosewhich are used preparation of Japanese traditional fermented foods andtempeh and which are safely used for foods, for example, thoseclassified as Aspergillus genus such as Aspergillus usamii, Aspergilluskawachi, Aspergillus awamori, Aspergillus saitoi, Aspergillus oryzae andAspergillus niger; and those classified as Rhizopus genus.

The fermentation time depends upon the type of koji mold used. However,it is at least 24 hours and is appropriately selected to be sufficientone for hydrolytically separating glycosidic saccharides from theisoflavone compounds contained in the defatted soybean to satisfactoryextent.

The temperature of the mixture in the device for preparing koji changeswith time, for example, as shown in FIG. 2, as koji preparationproceeds. That is, the temperature gradually rises until the state ofthe first agitation (mori) is reached 22 hours after the initiation ofthe koji preparation, and the temperature slightly falls past the firstagitation. Then, the temperature rises again until the stage of thesecond agitation (Naka) is reached 27 hours after the initiation of thekoji preparation. Upon stirring the mixture at the "intermediary", thetemperature slightly falls. Then, the temperature rises again until thestage of the third agitation (Shimai) is reached 32 hours after theinitiation of the koji preparation. Upon stirring the mixture at the thethird agitation (Shimai), the temperature slightly falls. Then, thetemperature rises again up to 40 hours after the initiation of the kojipreparation. Thereafter, the temperature gradually falls until the kojipreparation reaches completion 48 hours after the initiation of the kojipreparation.

Then, water is added to the product resulting from the koji preparation,and the mixture is kept in a heated condition at 30° to 65° C. for apredetermined period of time to hydrolyze protein while sufficientlyseparating glycosidic saccharides from the isoflavone compoundscontained in the defatted soybean by the action of β-glucosidasecontained in the product to form aglycones of isoflavones.

With respect to the hydrolysis of the protein, hydrolysis time andhydrolysis temperature are appropriately selected depending upon thetype of koji used so that glycosidic saccharides are separated from theisoflavone compounds contained in the defatted soybean to satisfactoryextent.

In this manner, organic acids are formed in the initial stage of thefermentation to inhibit contaminants in the defatted soybean frompropagating, thereby eliminating undesired possibility of secondarycontamination. Consequently, a product made from a defatted soybean as astarting material can be mass-produced. Further, even if the watercontent is not low, it is possible to carry out such treatment forseparating glycosidic saccharides from the isoflavone compoundssufficiently.

Table 2 shows contents of isoflavone compounds in 100 g of a defattedsoybean which is prepared by subjecting an untreated defatted soybean tokoji preparation initiated at an initial temperature of 30° C. andcompleted over a period of 48 hours, adding water to the resultingproduct in the same weight as that of the resulting product, andsubjecting the mixture to hydrolysis of proteins at 30° C. for 24 hours.

                  TABLE 2    ______________________________________    daidzin  daidzein     genistin                                  genistein    ______________________________________    25       74           53      59    ______________________________________     (unit: mg/100g)

According to Table 2, daidzein and genistein which are aglycones ofisoflavone compounds are contained in greatly increased amounts of 74 mgand 59 mg which are about 23 times and 14 times as large as the amountsthereof in the conventional example shown in Table 1, respectively. Fromthis, it is understood that daidzein and genistein can be formed infurther increased amounts by effecting the hydrolysis of proteins for 24hours or more after the completion of the koji preparation.

In another Example, the treatment according to the process of thepresent invention was applied to an untreated defatted soybean and a soyprotein isolate, and Table 3 comparatively shows, for the same purposeas that of Table 2, measurements thereon prior and posterior to thetreatment.

Explanation is first made with respect to one of them, the defattedsoybean. Proportions of starting materials and koji starter was suchthat 100 g of a defatted soybean, 0.1 g of a roughly polished rice, and8×10⁷ koji spores/g were used. With such proportions, the untreateddefatted soybean was subjected to koji preparation initiated at aninitial temperature of 30° C. and completed over a period of 48 hours,and water was added to the resulting product in the same weight as thatof the resulting product, and the mixture was subjected to hydrolysis ofproteins at 50° C. for 48 hours. The results are as shown in Table 3.

As the other of them, i.e., the commercially available soy proteinisolate, Fujinic 200 (trade name) manufactured by Fuji-Purina k.K. wasused. Proportions of starting materials and koji starter was such that100 g of the commercially available soy protein, 0.1 g of a roughlypolished rice, and 8×10⁷ koji spores/g were used. With such proportions,the untreated commercially available soybean protein was subjected tokoji preparation initiated at an initial temperature of 30° C. andcompleted over a period of 48 hours, and water was added to theresulting product in the same weight as that of the resulting product,and the mixture was subjected to hydrolysis of proteins at 50° C. for 48hours. The results are as shown in Table 3. Table 3

                  TABLE 3    ______________________________________                            commercially avail-             defatted soybean                            able soybean protein             pre   post         pre    post    ______________________________________    daizin     100     not detected 90   1.0    daizein    3.2     70           5.3  100    genistin   120     1.3          120  3.3    genistein  4.2     64           4.4  94    ______________________________________     (unit: mg/100g)

According to Table 3, in the defatted soybean, daidzein and genisteinwhich are aglycones of isoflavone compounds are contained in greatlyincreased post-treatment amounts of 70 mg and 64 mg which are about 22times and 15 times as large as the pre-treatment values, respectively.In addition, daidzin which is an isoflavone compound having a glycosidicsaccharide is decomposed to an undetectable extent, and the amount ofgenistin is extremely reduced to a level as low as 1.3 mg.

Likewise, in the commercially available soybean protein, daidzein andgenistein which are aglycones of isoflavone compounds are contained ingreatly increased post-treatment amounts of 100 mg and 94 mg which areabout 19 times and 21 times as large as the pre-treatment values,respectively. In addition, the amounts of daidzin and genistin which areisoflavone compounds each having a glycosidic saccharide are extremelyreduced to a level as low as 1.0 mg and 3.3 mg, respectively.

As described above, according to the present invention, of isoflavonecompounds contained in soybean, aglycones having high pharmacologicalactivities can be prepared at extremely high formation ratios.

In the next place, the process for preparing a product will be describedwhich comprises forming isoflavone compounds containing aglycones in alarge amount, and concurrently removing phytic acid contained in adefatted soybean.

The preparation procedure of the invention is conducted in substantiallythe same manner as in the previously described preparation procedure.However, in the koji preparation step, water addition step andhydrolysis step, phytic acid is removed from the defatted soybean inparallel with the formation of isoflavone compounds containing aglyconesin a large amount.

Then, each of these steps will be described.

In the koji preparation step, a mixture of a defatted soybean and kojistarter is charged into a device for preparing koji and kept in a heatedcondition at an initial temperature of about 28° to 30° C. for apredetermined period of time to ferment the defatted soybean havingwater content as low as 40% by weight by means of koji starter untilphytic acid in the defatted soybean is sufficiently removed.

In this case, koji mold is propagated on the defatted soybean to producephytase and phosphatase which are enzymes decomposing phytic acid, andby the enzymes, phytic acid in the defatted soybean is hydrolyticallyremoved.

Specifically, from phytic acid which is a compound having such astructure that myo-inositol has all of its hydroxyl groups each bondedwith a phosphoric acid group, the phytic acid-decomposing enzymesliberate the phosphoric acid group(s) to form inositol pentaphosphate,inositol tetraphosphate, inositol triphosphate, inositol diphosphate,inositol monophosphate or inositol alone or a mixture thereof, therebyremoving phytic acid.

As the koji starter for the koji preparation, there may be used kojimolds which are used preparation of Japanese traditional fermented foodsand tempeh and which are safely used for foods, for example, thosehaving high phytase and phosphatase potency and classified asAspergillus genus such as Aspergillus usamii, Aspergillus kawachi,Aspergillus awamori, Aspergillus saitoi, Aspergillus oryzae andAspergillus niger; and those having high phytase and phosphatase potencyand classified as Rhizopus genus.

The fermentation time depends upon the type of koji mold used. However,it is at least 24 hours and is appropriately selected to be sufficientone for removing phytic acid contained in the defatted soybean tosatisfactory extent.

In the subsequent water addition step and hydrolysis step, water isadded to the product resulting from the koji preparation, and themixture is kept in a heated condition at 30° to 55° C. for apredetermined period of time to hydrolyze protein while sufficientlyreducing the amount of phytic acid contained in the defatted soybean bythe hydrolytic action of phytase, phosphatase and/or protease containedin the product.

With respect to the hydrolysis of protein, hydrolysis time andhydrolysis temperature are appropriately selected depending upon thetype of koji used so that phytic acid contained in the defatted soybeanis sufficiently removed.

The removal of phytic acid is effected by liberating at least onephosphoric acid group from phytic acid which is inositol hexaphosphate.In this connection, however, at least two phosphoric acidgroups-liberated resultants, i.e., inositol tetraphosphate, inositoltriphosphate, inositol diphosphate, inositol monophosphate and inositolare water-soluble and have activities to greatly facilitate absorptionof a mineral such as calcium contained in a product made from a cereal.

Further descriptively, the above-mentioned inositol hexaphosphate andinositol pentaphosphate have strong ion capturing activities and preventcaptured calcium ion from being liberated, thereby strongly inhibitabsorption of calcium. On the other hand, inositol tetraphosphate toinositol monophosphate have such preferable affinities that theypreferably capture calcium but readily liberate captured calcium onoccasion, thereby exhibiting characteristic activities to facilitateabsorption of calcium.

It is, therefore, preferred to effect removal of phytic acid byliberating at least two phosphoric acid groups from phytic acid which isinositol hexaphosphate to form inositol tetraphosphate, inositoltriphosphate, inositol diphosphate, inositol monophosphate or inositolalone or a mixture thereof, thereby obtaining a product which enablesminerals to be absorbed efficiently. In this case, it is preferred tocontrol the number of the phosphoric acid groups liberated from phyticacid by adjusting the fermentation time, and hydrolysis time andhydrolysis temperature depending upon the type, state, properties andamount of the pulse crop, the type, state, properties and amount of thekoji, and type and properties of the intended product.

Table 4 shows phytic acid content in 100 g of a defatted soybean, withrespect to an untreated defatted soybean; defatted soybeans A and Bwhich are prepared using two different shochu kojis (Aspergillus nigerand Aspergillus awamori) and each prepared by subjecting a defattedsoybean to koji preparation initiated at an initial temperature 30° C.and completed over a period of 48 hours, adding water to the resultingproduct in the same weight as that of the resulting product, andsubjecting the mixture to hydrolysis of protein at 30° C. for 24 hours;and a defatted soybean subjected to conventional washing treatment withan alcohol.

                  TABLE 4    ______________________________________    defatted soybean  phytic acid content (mg/100g)    ______________________________________    untreated defatted soybean                      999 (mg/100g)    shochu koji-treated d. s. A                      not detected    shochu koji-treated d. s. B                      not detected    alcohol-washed d. s.                      1,150 (mg/100g)    ______________________________________     (detection limit: 5mg/100g)

According to Table 4, in contrast to the phytic acid content of 999 mg(about 1%) in the untreated defatted soybean, no substantial phytic acidcontents in the defatted soybeans A and B are detected, which are eachprepared according to the present invention by subjecting an defattedsoybean to shochu koji treatment, adding water to the resulting productin the same weight as that of the resulting product, and subjecting themixture to hydrolysis of proteins at 30° C. for 24 hours. In otherwords, almost all phytic acid is decomposed in each of the defattedsoybeans A and B.

On the other hand, the phytic acid content in the defatted soybeansubjected to the conventional washing treatment with an alcohol is 1,150mg and no reduction of the phytic acid content is observed.

As described above, according to the present invention, of isoflavonecompounds contained in soybean, aglycones having high pharmacologicalactivities can be prepared at extremely high formation ratios, and atthe same time, phytic acid content in soybean can be greatly or almostcompletely reduced.

Next, a food containing the product made from a pulse crop according tothe present invention will be described.

The food containing the product made from a pulse crop according to thepresent invention includes a food consisting only of the product madefrom a pulse crop which is prepared in accordance with the process ofthe present invention and a food containing the product in part.

The product made from a pulse crop as a starting material which isprepared in accordance with the process of the present invention is afood having an extremely low salinity, because it is prepared withoutbeing salified with common salt. Accordingly, the product can beingested in a sufficient amount when served as a food. And yet, the foodcontains aglycones of isoflavones in a large amount, which exhibitexcellent carcinopreventive and carcinostatic activities, osteoprosistherapeutic effect and immunosuppressive effect, thereby enablingdietarily desired life to be realized which exhibits excellent effect interms of health maintenance of a human being.

For example, when the food containing the product made from a pulse cropaccording to the present invention is formed into a form convenient foreating such as a biscuit, cookie or the like, it is possible to ingestaglycones of isoflavones which have excellent carcinopreventive andcarcinostatic activities, osteoprosis therapeutic effect andimmunosuppressive effect while such an article is eaten as a food. Inparticular, by simply eating such a biscuit or the like in an amountcovering the intake of aglycones of isoflavones per day which isrequired to attain carcinopreventive and carcinostatic effect,osteoprosis therapeutic effect and immunosuppressive effect, the biscuitor the like contributes to prevention of outbreak of the disorders.

Of these aglycones of isoflavones, genistein is effective for preventionand carcinostasis at an initial stage of mastocarcinoma, prostatiticcancer and the like. Accordingly, ingestion of the food containing theproduct made from a pulse crop according to the present inventioncontributes to prevention of outbreak of these cancers, thereby enablingdietarily desired life in terms of health maintenance to be realized.

Further, with respect to osteoprosis, while aglycones of isoflavonesexhibit osteopenia preventive effect, the removal of phytic acid enablesa vitamin B complex having growth promoting activities andantiadipohepatic activities and the like to be maintained highly activeand hence exhibits facilitative effect on absorption of calciumcontained in the pulse crop. Moreover, these effects synergesticallyprovide a food having extremely excellent osteoprosis therapeuticeffect. In particular, such a food exhibits significant effect when usedin dietotherapy for a person hormone-relatedly susceptible toosteoprosis.

When the defatted soybean prepared in accordance with theabove-described procedure is utilized as a feed or the like, as shown inFIG. 1, the defatted soybean prepared as in the above-describedembodiments is dried and then pulverized to obtain a product as apulverized defatted soybean having high pharmacological activities, suchas a material for a livestock feed, an aquacultural feed or the like.

According to the present invention, formation of aglycones of isoflavonecompounds contained in a pulse crop, which have high pharmacologicalactivities, at an extremely high formation ratio; removal of phytic acidin the pulse crop; and hydrolysis of proteins are effected bypropagation of living koji. Therefore, the formation of aglycones andthe removal of phytic acid can be attained even if the pulse crop is insolid state or fluid state, thereby enabling simplified preparationprocedure and reduced preparation cost to be realized.

Further, the preparation process of the present invention can be carriedout using a conventional device for preparing koji without anyalteration, and hence a basic device for production is not required tobe specially manufactured, thereby providing wide utility.

It is to be noted that the present invention is by no means restrictedto the above-described embodiments and that various alterations andmodifications can be made according to need.

We claim:
 1. A process for preparing a product from a pulse crop as astarting material which comprises the ordered steps of:preparing a kojipreparation by the steps comprising:cooking said pulse crop, coolingsaid cooked pulse crop, adding water into said pulse crop, mixing a kojistarter into said pulse crop, incubating said pulse crop while stirring,and hydrolyzing said koji preparation by adding water, whereby phyticacid contained in said pulse crop is removed and glycosidic saccharidescontained in said pulse crop are hydrolyzed, thereby forming isoflavonecompounds containing aglycones.
 2. A process according to claim 1,wherein said pulse crop is kept between 30°-40° C. during said step ofpreparing a koji preparation.
 3. A process according to claim 1, whereinsaid glycosidic saccharides contained in said pulse crop are convertedinto aglycones.
 4. A process according to claim 1, wherein said kojistarter comprises Aspergillus.
 5. A process according to claim 1,wherein said step of hydrolyzing said koji preparation comprises addinga quantity of water approximately equal in weight to the weight of saidkoji preparation.
 6. A process for preparing a product in a bulkquantity from a pulse crop as a starting material which comprises theordered steps of:preparing a koji preparation by the stepscomprising:cooking said pulse crop, cooling said cooked pulse crop,adding water into said pulse crop, mixing a koji starter into said pulsecrop, incubating said pulse crop while stirring, and hydrolyzing saidkoji preparation by adding a quantity of water approximately equal inweight to the weight of said koji preparation and keeping said kojipreparation at 30°-65° C. for approximately 48 hours, whereby phyticacid contained in said pulse crop is removed and glycosidic saccharidescontained in isoflavones are converted into aglycones.
 7. A food productprepared from a pulse crop as a starting material, said product beingprepared by the ordered steps of:preparing a koji preparation by thesteps comprising:cooking said pulse crop, cooling said cooked pulsecrop, adding water into said pulse crop, mixing a koji starter into saidpulse crop, incubating said pulse crop while stirring, and hydrolyzingsaid koji preparation by adding water, whereby phytic acid contained insaid pulse crop is removed and glycosidic saccharides contained in saidpulse crop are hydrolyzed, thereby forming isoflavone compoundscontaining aglycones.
 8. A food product prepared from a pulse crop as astarting material, said product being prepared by the ordered stepsof:preparing a koji preparation by the steps comprising:cooking saidpulse crop, cooling said cooked pulse crop, adding water into said pulsecrop, mixing a koji starter into said pulse crop, and incubating saidpulse crop while stirring; hydrolyzing said koji pulse crop by adding aquantity of water approximately equal in weight to the weight of saidkoji preparation and keeping said koji preparation at 30°-65° C. forapproximately 48 hours, whereby phytic acid contained in said pulse cropis removed and glycosidic saccharides contained in isoflavones areconverted into aglycones.
 9. A food product prepared from a pulse cropas a starting material according to claim 8, further comprising a stepof drying said koji pulse crop after said hydrolyzing step.
 10. A foodproduct prepared from a pulse crop as a starting material according toclaim 9, further comprising a step of pulverizing said koji pulse cropafter said drying step.